透過調整人體質心與壓力中心之參考軌跡達成平衡控制

Abstract

在此篇論文中我們提出控制模擬角色達成指定的動作之方法。透過動量控制，我們可以藉由控制角色的質心和壓力中心來維持角色平衡。為了要控制角色的質心與壓力中心，控制器需要追尋它們的參考軌跡。基於地面反作用力之考量，我們的方法能動態調整質心之參考軌跡以產生高自然度的動作模擬。另外由於參考動作中缺乏壓力中心之相關資訊，我們在考慮支撐腳的腳踝力矩下利用已調整之質心參考位置來決定壓力中心之參考位置。我們的最佳化機制利用動量及軌跡追尋等目標函式計算出下一刻模擬之最佳角速度。給予一參考動作或參考姿勢，我們的控制器可以在存在外力干擾下維持角色全身平衡。我們最後說明在不同環境中我們的控制機制可以模擬角色在原地及移動下平衡。

In this thesis, we present an approach for simulated characters to perform specific motions. Using a momentum-based technique, our controller can maintain a simulated character's balance by controlling the character's center of mass (CoM) and center of pressure (CoP). In order to control the CoM and the CoP, the controller needs to follow reference trajectories of the CoM and the CoP. Based on the ground reaction forces, we propose a novel method to dynamically adjust the reference CoM for generating physically plausible and natural motions. In addition, due to lack of information about the CoP in reference motions, we determine the reference CoP according to the adjusted reference CoM by considering the moment of force acting at the supporting ankle joint. Our multi-objective optimization technique, including momentum and tracking objective terms, solves the optimal joint velocities for the next time step. Given a motion capture or key-frame data, our controller can maintain the full-body balance in presence of disturbances while tracking a specific motion simultaneously. We demonstrate our results that our control scheme is capable of standing and locomotion simulation in varying environments.